The invention relates to a starter unit, and a method for matching starter units in drive systems to different limiting conditions, in particular different drive engines.
Starter units for use in manual transmissions, automatic transmissions and automated gears are known. As a rule, these encompass a hydrodynamic design element in the form of a hydrodynamic revolution/torque converter or a hydrodynamic coupling. DE 198 04 635 A1 relates to a feasible execution of a starter unit for use in gears with a hydrodynamic coupling. This document discloses an execution of a starter unit with a short axial design length, encompassing a pump wheel and a turbine wheel that together form a toroidal working chamber, whereby the pump wheel is arranged on the motor drive side, i.e. the turbine wheel is spatially arranged between the input of the starter unit and the pump wheel. For this purpose, the pump wheel is connected in a rotationally fixed manner with the input and with a rotationally fixed drive coupled with the input via an element, which simultaneously forms the pump wheel shell. There is a bridge coupling placed parallel to the hydrodynamic coupling. This enables power transfer from the input of the starter unit to the output through circumvention of the hydrodynamic design element. The bridge coupling is thereby arranged as a separate design element next to the unit out from the pump wheel and turbine wheel. Furthermore, the starter unit encompasses a device for attenuation of oscillations, which is placed in a diameter area which is arranged above the extreme radial measurement of the toroidal working chamber of the hydrodynamic coupling and is a component of the bridge coupling and forms a coupling element. In other words, the device oscillation attenuation is essentially on the area of a plane or slightly set against the hydrodynamic coupling. This solution has relatively short build but does not, however, fulfill the requirements of certain prescribed installation situations with respect to the required axial design length. Furthermore, this execution is characterized by a high number of design components and enormous assembly effort due to the high number of functional elements. The size of the starter unit is also determined by the required layout of the unit in combination with a drive engine and the subordinated gear levels used in drive systems. In particular, a change in the drive engine requires a change in the layout of the starter unit.
The invention is therefore intended for the task of further developing a starter unit of the type mentioned above, encompassing a hydrodynamic coupling, that may be reversed in parallel manner, as well as in its individual elements in such a way that these elements can be used universally for a majority of drive belts with different limiting conditions, e.g. drive engines of differing power, without changing the design layout. In addition, the starter unit should be characterized by a very small design space requirement in an axial direction, a small number of design parts and the combination of function elements. The design effort must be kept small.